Perception-Augmenting Illumination

Veronika Šoltészová

PHDTHESIS,
Aug, 2012

Abstract

At each stage of the visualization pipeline, the information is impeded
by loss or by noise because of imprecise acquisition, storage limitations, and
processing. Furthermore, it passes through the complex and not yet well understood
pathways in the human visual system and finally to result into a mental image. Due
to the noise that impedes the information in the visualization pipeline and the
processes in the human visual system, the mental image and the real-world phenomenon
do not match. From the aspect of physics, the input of the visual system is confined
only to patterns of light. Illumination is therefore essential in 3D visualization
for perception of visualized objects. In this thesis, several advancements for advanced
volumetric lighting are presented. First, a novel lighting model that supports
interactive light source placement and yields a high-quality soft shadowing effect,
is proposed. The light transport is represented by conical functions and approximated
with an incremental blurring operation of the opacity buffer during front-to-back
slicing of the volume. Furthermore, a new perceptuallyfounded model for expressing
shadows that gives a full control over the appearance of shadows in terms of color
and opacity, is presented. Third, a systematic error in perception of surface slant
is modeled. This knowledge is then applied to adjust an existing shading model in a
manner that compensates for the error in perception. These new visualization
methodologies are linked to the knowledge of perceptual psychology and the
craft of illustrators, who experimented with visual-presentation techniques for centuries.
The new methodologies are showcased on challenging acoustic modalities such as 3D
medical ultrasound and sonar imaging.

Published

ISBN: 978-82-308-2118-3

School: Department of Informatics, University of Bergen, Norway

Date: Aug 2012

Media

BibTeX

@phdthesis{solteszova12thesis,
title = {Perception-Augmenting Illumination},
author = {Veronika \v{S}olt{\'e}szov{\'a}},
year = {2012},
month = {Aug},
abstract = {At each stage of the visualization pipeline, the information is impeded
by loss or by noise because of imprecise acquisition, storage limitations, and
processing. Furthermore, it passes through the complex and not yet well understood
pathways in the human visual system and finally to result into a mental image. Due
to the noise that impedes the information in the visualization pipeline and the
processes in the human visual system, the mental image and the real-world phenomenon
do not match. From the aspect of physics, the input of the visual system is confined
only to patterns of light. Illumination is therefore essential in 3D visualization
for perception of visualized objects. In this thesis, several advancements for advanced
volumetric lighting are presented. First, a novel lighting model that supports
interactive light source placement and yields a high-quality soft shadowing effect,
is proposed. The light transport is represented by conical functions and approximated
with an incremental blurring operation of the opacity buffer during front-to-back
slicing of the volume. Furthermore, a new perceptuallyfounded model for expressing
shadows that gives a full control over the appearance of shadows in terms of color
and opacity, is presented. Third, a systematic error in perception of surface slant
is modeled. This knowledge is then applied to adjust an existing shading model in a
manner that compensates for the error in perception. These new visualization
methodologies are linked to the knowledge of perceptual psychology and the
craft of illustrators, who experimented with visual-presentation techniques for centuries.
The new methodologies are showcased on challenging acoustic modalities such as 3D
medical ultrasound and sonar imaging.},
school = {Department of Informatics, University of Bergen, Norway},
ISBN = {978-82-308-2118-3},
}